Recovery of HIV antigen in peritoneal dialysis fluid

We investigated the presence of HIV antigen in dialysis fluid of patients with end-stage renal disease (ESRD) undergoing continuous ambulatory peritoneal dialysis (CAPD), previously known to be infected with this virus. Sixteen adult patients and 6 adult volunteers were included in the study in 4 groups as follows: Group A: 3 patients on CAPD, previously known to be positive for serum HIV antibodies; Group B: 7 patients on CAPD, serum HIV negative; Group C: 6 AIDS patients without renal disease; and Group D: 6 healthy volunteers. Of the 3 patients of Group A, the HIV-1 Ag was positive in dialysis fluid in only 2. In 1, serum Ab and Ag were present, while in the others only serum Ab was detected. The samples from Group B were all negative for the viral antigen in dialysis fluid. We conclude that dialysis fluid of HIV-infected patients may contain the Ag and is therefore potentially infective. The presence of the HIV antigen was not constant, and was not related to antigenemia. It is possible that the presence of the Ag depends on local factors that influence viral replication or to alterations in the permeability of the peritoneal membrane. We discuss other possible factors that could influence the presence of viral Ag in peritoneal dialysis fluid.